John ericsson



J'. ERICSSONS.

AIR ENGINE.

Patented Oct. 9, 1860.

UNITED STATES PATENT OFFICE.

JOHN ERICSSON, OF NEIV YORK, N. Y.

AIR-ENGINE.

Specification of Letters Patent No. 30,306, dated October 9, 1860.

T 0 all whom it may concern:

Be it known that I, JOHN EnIossoN, of the city, county, and State of NewYork, have invented certain new and useful Improvements in Air-Engines;and I do hereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawing, forming part of this specification, said drawing representing acentral longitudinal vertical section of an air-engine constructedaccording to my invention.

In all air engines operated under condensed pressure as hithertoconstructed the motive force of the working piston has been foundinadequate, owing principally to the rapid diminution of the actingpressure by expansion, during the movement of the piston from end to endof the cylinder.

One great object of my invention is not only to obviate such diminutionof the acting pressure toward the end of the stroke but to augment thesame as well as the effective force of the piston, as it approaches thetermination of the stroke. This I accomplish by placing two cylinderswhich I call equilibrium cylinders in a direct line at a certaindistance from each other. Close to these cylinders I place a strong airtight vessel or series of vessels to which heat is applied, and alsoanother strong air tight vessel or series of vessels kept cool by theapplication of cold water of currents of atmospheric air. Vithin each ofthe equilibrium cylinders a hollow piston which I call the equilibriumpiston is made to operate, and both pistons are connected by a longpiston of relatively small diameter resembling the ram of a hydraulicpress. This piston which I call the working piston passes through airtight stuffing boXes in the heads of the equilibrium cylinders. Theworking piston is connected with the driving crank of the engine by across head and side rods, or by beams and connecting rods as in steamengines. By means of an air pump operated by auxiliary power,atmospheric air is charged into the equilibrium cylinders, heater andcooler, but in such amanner that a greater pressure is charged into theheater than into the cooler. The pressure in the equilibrium cylinderswill vary as will be explained hereafter.

By means of certain connecting pipes and valves I establish analternating communication, between the heater, cooler and equilibriumcylinders, the arrangement being such, that both ends of one equilibriumcylinder are simultaneously in free communication with the heater whileboth ends of the other equilibrium cylinder are at the same time in freecommunication with the cooler. The pressure in the heater being greaterthan on the cooler the working piston will be forced from or out of thecylinder which is in communication with the heater into the cylindercommunicating with the cooler. lVhen the working piston has completedthe stroke the communications between the equilibrium cylinders, heaterand cooler are reversed by valves operated as in non expansive steamengines, and thus a continuous motion is produced. The greater volume ofair withdrawn from the heater is compensated by the dilatation caused byheating the air during its passage through the heater or heaters, all ofwhich will be hereafter more fully explained.

In the accompanying drawing a, and b, are cylinders placed in a directline with each other provided with close heads at both ends. Thesecylinders I call equilibrium cylinders.

c is a piston resembling the rain of a hydraulic press to be made eitherhollow or solid. This piston I call a working piston which passesthrough the heads of the equi librium cylinders with air tight packingsat 0, c, and is connected to a crank cl, on the driving shaft 6, bymeans of a connecting rod cl, and a cross head cl, fixed 1n the workingpiston.

f, and g, are hollow pistons fitted easily in the cylinders a, and b,filled with pounded charcoal and attached at opposite ends of theworking piston c.

h, is a strong air tight vessel placed near the equilibrium cylinderspartially filled with a number of disks of wire cloth. I call thisvessel a heat deposit vessel. 2', is another strong air tight vesselsurrounded by brick work with fire places at i, i, and a flue 2",connected with a smoke pipe in a chimney.

7c, is a strong air tight vessel provided with head plates is, and headchambers Z, and m, these latter being put in communication by a seriesof small tubes inserted in the head plates. n, is a strong air tightvessel to act as a cooler either by being freely exposed to theatmosphere or by being immersed in a surrounding cistern of cold wateror other means usually adopted for purposes of refrigeration.

a, and b, are pipes for forming a communication between the equilibriumcylinders and heater.

Z, is a pipe communicating between the head chamber Z, and the cooler a.

Z, is a pipe communicating between the vessel is, and the heater 7:.

h, it, h, is a bent pipe for forming a communication between the twoextreme ends of the equilibrium cylinders and the head chamber m.

0, is a stop cock for opening or shutting off the communication betweenthe pipes at, and Z.

2), is a pipe communicating between the heat deposit vessel It, and thevessel is.

g, is a pipe through which the heater and other parts may be chargedwith compressed atmospheric air.

l, 2, 3, 4:, 5, and 6, are valves operated by ordinary valve gearattached to the crank shaft in such a manner that l and 2, open thecommunication alternately between the cooler and equilibrium cylinders,while the pistons f, and g, move respectively toward the extreme outerends of the cylinders. The valves 3, and 4:, communicate between thecylinders and heat deposit vessel while the said pistons moverespectively toward the inner heads. The valve 5, operates so as to formcommunication between a, and a, when the equilibrium piston f, moves tothe right, and a communication between a, and 72,, when the piston movesto the left. In like manner the valve 6, communicates between ?2, andit, when the piston 9, moves to the right and between 6, and b, when itmoves to the left. Having now described the various parts of my improvedair engine I will now explain the manner of putting the same intooperation.

Compressed air is charged into the interior of the engine through thepipe 9, by means of an air pump actuated by auxiliary power. It will beseen by inspecting the drawing that the compressed air will enter theheater 2', first, and from thence to the vessels is, and h, and also theequilibrium cylinder (4 through the valves 3, and 5. As the equilibriumcylinder 6, is at the same time in communication with the cooler bymeans of the valve 2, and 6, and the various pipes before described itwill be seen that the pressure in a, owing to its more immediateconnection with the heater z', will force the working piston a, into theequilibrium cylinder 6, until it reaches the termination of the strokewhen the position of the valves is reversed as before stated. A lefthanded movement of the piston will then take place in like manner by theequilibrium cylinder 5, being in communication with the heater while a,is in communication with the cooler, In this manner a continuousreciprocating motion will be kept up as in a steam engine. It is properhere to state that the heated air as itpasses off from the equilibriumcylinders through the valves 5, and 6, the pipe h, and head chamber m,gives out its heat to the numerous tubes in the vessel 70. On the otherhand the cold air from the opposite end of the equilibrium cylindersafter having passed through it, and p, comes in contact with the heatedtubes and therefore when enteringthe heater at Z, a very considerableelevation of temperature has been effected which will materially assistthe heater. In like manner the heat'lost by the exhaust air in passingthrough the tubes of k, will materially assist the cooler in reducingthe temperature of the air before it enters the equilibrium cylindersthrough the valves 1, and 2. I have further to state that if the coolerat, be removed and the air from Z, be permitted to escape into theatmosphere and if the valves 1, and 2, open directly into the atmospheremy improved air engine will operate well and prove of great practicalutility. Itspower will however be greatly increased by applyingthe-cooler and charging the interior with air of greater density thanthe atmosphere.

It will be seen that the wire disks inserted.

into the vessel It, will efiectually take up the heat which otherwisewould enter the cold end of the equilibrium cylinders through the valves3, and 4, on opening these for establishing equilibrium of pressure inthe cylinder. The heat thus imparted to the wires will in turn be takenup by the cold air as it passes of? from the cylinders to the heaters.

It is evident that the exhaust valves 3, and 4, need not be opened untilthe compression of the cold air has established an equilibrium ofpressure at both ends of the cylinders, and it is also evident that theinlet ports of the valves 5, and 6, may be closed somewhat before thetermination of the stroke of the piston. An increase of motive powerwould attend the mode of opening and closing the valves now stated, butas the strain on the working gear of the engine would be increased in anearly quadruple ratio, I prefer to open and close the valve asdescribed. It is also evident that the two equilibrium cylinders withtheir pistons may be placed side by side, and that the working pistonmay be divided ttransversely through its middle thereby forming twopistons, and that the two pistons thus formed may be connected by beamby which a reciprocating movement would be produced and motive powerobtained precisely as described. It is also evident that the heaters andcoolers may be placed in various positions provided they are connectedwith the equilibrium cylinder as described. I do not therefore confinemyself to the precise arrangement there shown.

What I claim as my invention and desire to secure by Letters Patentis 1. The combination of the equilibrium cylinders a, Z), theequilibrium pistons f, g, and the working piston 0, when usedsubstantially in the manner and for the purposes above set r'ort-h.

2. The combination of the equilibrium cylinders (a 1), the equilibriumpistons f, g, the valves 5, and 6, the vessel 70, and the tubes thereincontained when used substantially in the manner and for the purposesabove set forth.

3. The combination of the equilibrium cylinders a, 7), the equilibriumpistons f, g, the valves 3, and 4: and the heat deposit vessel h, whenused substantially in the manner and for the purposes above set forth.

4. The combination of the equilibrium cylinders a, b, the equilibriumpistons f, g, the valves 5, and 6, and the heater 2', when used in themanner and for the purposes above set forth.

5. The combination of the equilibrium cylinders a, b, the equilibriumpistons f, g, the valves 1, and 2, and the cooler 7%, when used in themanner and for the purposes set forth.

(3. The combination of the equilibrium cylinder a, the equilibriumpiston f, the valve 5, and the bent pipe h, h, h, when used for thepurposes above set forth.

J. ERICSSON.

Witnesses:

M. M. LIVINGSTON, J NO. A. Sco'rT.

